认知无线电中认知用户的重新建模与性能分析

针对认知网络频谱接入问题,讨论了以往建模和理论分析中存在的不足.为了真实地模拟授权用户和认知用户的行为,对频谱接入策略重新进行建模,并利用矩阵几何法和离散事件系统仿真的事件调度法重新评估和比较了不同接入策略下的认知系统性能,针对不同业务类型选取最佳接入策略.理论分析和仿真实验结果一致,验证了所提模型的可靠性.频谱切换和信道预留接入策略增大了阻塞率并有效地降低了掉话率,后者通过调整预留信道数目使认知系统吞吐量最大.

Performance analysis and re-modeling of secondary users in cognitive radio system

A number of errors in the past Markov model and theoretical analysis were discussed in spectrum access based on cognitive radio network (CRN).To imitate the behav ary user (PU) and secondary user (SU) factually,new models for access strategy were presented.The performance of CRN based on different access strategies were reappraised and compared by using matrix geometric theory and event scheduling of discrete events system simulation.Theoretical analysis results and simulation experiments were tally close,which confirms the reliability of proposed models.The access strategies with handoff and channel reservation efficiently decrease the call dropping probability,as while as,increase the blocking probability.And the thought for CRN can reach the maximum in the latter with the optimum number of reserved channels.